1. Field of the Invention
This invention relates to monoclonal antibodies characterized by their specificity to human lung cancer, in particular human pulmonary adenocarcinoma, and that the antigens (epitope) recognizable by them are sialylated glycoproteins or glycolipids, and to the use thereof in pathologic or serologic diagnosis or monitoring of pulmonary adenocarcinoma patients.
2. Description of the Prior Art
Methods of producing monoclonal antibodies capable of reacting specifically with tumors which comprise cultivating hybridomas obtained by fusing antibody-producing cells from an immunized animal with myeloma cells have recently been reported. It has been reported as well that monoclonal antibodies to human lung cancer can be obtained by such a technique [Cancer Res., 42, 150 (1982); Cancer Res., 42, 3187 (1982): J. Surgical Res., 30, 403 (1981); Transplantation Proceed., XIII (4), 1942 (1981); J. Immunol., 131 (1), 497 (1983); Abstracts of Papers, Japan Society of Immunology, P. 212 (Seishi Kyoizumi: Abstract No. 107) (1983)]. However, most of those monoclonal antibodies can react also with cancers other than lung cancer or with normal human cells; few are specific to lung cancer. Even those monoclonal antibodies that can be said to be relatively specific to lung cancer [J. Immunol., 131 (1), 497 (1983)] cannot distinguish such tissue types as squamous cell carcinoma and adenocarcinoma, although they can distinguish non-small cell from small cell lung cancer. No monoclonal antibodies applicable in serum diagnosis of lung cancer have not yet been reported.
A technique of serum diagnosis of digestive tract cancers using anti-human digestive tract cancer (stomach cancer, pancreas cancer, colon cancer) monoclonal antibodies has recently been reported. These monoclonal antibodies all recognize sialylated glycoproteins as serum antigens [J. Clin. Immunol, 2, 135 (1982); Federation Proc., 41, 898 (1982); Cancer Res., 42, 601 (1982); Hybridoma, 2, 110 (1983)]. On the other hand, monoclonal antibodies to lung cancer that recognize sialylated glycoproteins or glycolipids have not been reported at all.
Monoclonal antibodies reacting specifically with lung cancer, if available, would be useful in the diagnosis of lung cancer. While monoclonal antibodies to lung cancer are known, development of superior antibodies is desired. The present inventors have found that monoclonal antibodies produced by hybridomas between spleen cells of an antibody-producing mouse immunized with human pulmonary adenocarcinoma tissue membrane components, and mouse myeloma cells have particularly good reactivity with pulmonary adenocarcinoma and applicable in serum diagnosis of lung cancer and have now completed the present invention based on this finding.